The New York structure is the first tower Mr Libeskind has designed, having until now been most renowned for designing the Jewish Museum in Berlin.

BBC: NEWS | Americas | Architect 'in control' of WTC plans

Mr Libeskind, who designed the Jewish Museum in Berlin has described his collaboration with Childs as a "forced marriage", but it was all smiles at the news conference.

BBC: NEWS | Americas | Freedom Tower plan for WTC site

In 1999 his first high profile work - the Jewish museum in Berlin - opened after 10 years construction, followed in 2002 by the Imperial War Museum in Manchester.

BBC: Daniel Libeskind: Visionary architect

Mr Libeskind, who designed the Jewish Museum in Berlin, would like to keep much of the gaping hole left at the World Trade Center site for space for an eventual memorial.

BBC: Berlin architect to rebuild WTC site

The new Jewish museum in Berlin cancelled its public opening set for Tuesday night.

CNN: Attacks spark global red alert

This is something Daniel Libeskind knows all about, after 10 years on the job in Berlin guiding his competition-winning Jewish Museum to completion.

WSJ: Daniel Libeskind Envisions Ground Zero